You are downloading the ArcGIS XAP file v10.1.3.0 for Windows Phone. ArcGIS is a free and useful Productivity app: ArcGIS is a great way to discover and use maps. Maps come to life in ArcGIS. Tap the map, or use your current location and discover information about ... You can now download the offline XAP file to install & try it.
Download Locations for ArcGIS 10.1.3.0 XAP file
Note: To install it manually from an SD card, you should choose one of the server location above to get the offline ArcGIS XAP file, move the file to your phone's SD card and then tap 'Install local apps' in the phone's App list.